Let me explain better with examples:
- the presence of the assassin created the tension to react at the moment of her search for the enemy;
- the sniper was looking at you and you had to pay attention to her laser.
- the heavy unit created strong tension from its sudden charge
- the bastion could destroy you if you didn’t stay behind a shield.
The units of the PVE seem to me … a lot, maybe too much “shoot us when you want”. I like that they lose specific body pieces if you focus on them, but it’s more like playing Diablo. and this to me is what people then perceive as “we see that the talent trees were foreseen, to let players vent with more confusion with messy power-ups”. there are very few units that create a variation of tactics but… don’t involve the whole team to deal with them.